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Calculate inter-rater reliability for each dimension using the intraclass correlation and ordinal Krippendorff's alpha. The function also reports missing ratings and the number of complete materials used for the ICC.

Usage

rater_reliability(ratings)

Arguments

ratings

A long ratings tibble with a rater column.

Value

A tibble with one row per dimension: n_raters, n_materials, n_complete (materials every rater scored, which is what the ICC is computed on), n_failed, icc_single (ICC(A,1), the reliability of one rater), icc_average (ICC(A,k), the reliability of their mean), and krippendorff_alpha.

Report icc_single when a single rating is the unit of analysis and icc_average when you average raters first. They can differ a lot: .67 and .89 on the same data is typical.

Details

I'd specify whether I'm reporting the reliability of one rater or the mean of several. I'd also be careful interpreting high agreement among repeated calls to the same model: the raters share a model, and agreement among them doesn't establish agreement with people.

Examples

r <- data.frame(
  material_id = rep(paste0("m", 1:4), times = 2),
  condition   = rep(c("a", "a", "b", "b"), times = 2),
  rater       = rep(c("synthetic_1", "synthetic_2"), each = 4),
  dimension   = "tone",
  rating      = c(5, 6, 2, 3, 5, 5, 2, 4)
)
rater_reliability(r)
#> # A tibble: 1 × 8
#>   dimension n_raters n_materials n_complete n_failed icc_single icc_average
#>   <chr>        <int>       <int>      <int>    <int>      <dbl>       <dbl>
#> 1 tone             2           4          4        0      0.903       0.949
#> # ℹ 1 more variable: krippendorff_alpha <dbl>